I wrote a short article on glucosamine and tendon pain a little while ago, but I’ll just post quickly about the subject here. Basically, there are websites out there that try to sell you glucosamine for tendon problems. It works nicely for joints, so I guess that they figure it will work for tendons as well.
The problem is, tendons aren’t joints. Joints are made up of cartilage, which glucosamine helps the body to form, but tendons are made up of collagen. Tendons have blood vessels in them, joints don’t. And so on. Physiologically, they’re completely different tissues.
If you have joint pain, then by all means try glucosamine. It’ll probably help. But selling the stuff for tendon pain is nothing more than preying on the gullibility and medical ignorance of the general populace. It’s a rip-off, and any website that lists it for tendonitis, tendonosis or any other form of tendonopathy should be completely avoided.